Parts of the U.S. Capitol are being cleared after authorities announced suspicious packages on the first and third floors of the Hart Senate Office Building and a suspicious envelope in the Russell Senate Office Building at the office of Sen. Richard Shelby of AlabamaCapitol Hill Police are questioning a man with a backpack in the area of the Hart office building. The man raised suspicion with the content of his backpack and how he responded to police questions, two Capitol Hill police officers said. The man's backpack contained more sealed envelopes, one of the officers said.